Cocking mechanism



April 14, 1942. w. SUMMERBELL COOKING MECHANISM Filed May 16, 1941 lNVENTOR ATTORNEYS I? William Summer-hall Y r mm [III/III. I1

Patented Apr. 14, 1942 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 3 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a cocking mechanism for a gun of the type having a vertically sliding breech block. The firing mechanism employed forms the subject matter of my copending application, Serial No. 274,987 and the cocking mechanism represents an improvement over that shown in that application.

It is the object of this invention to provide a cooking mechanism which is automatically actuated by the operation of the breech block and which will be simple and reliable in its functioning.

It is a further object of my invention to sim plify the assembly and maintenance of the cocking mechanism.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a, preferred embodiment as shown in th accompanying drawing in which:

Figure l is a side elevation, partly in section of the breech mechanism with the breech in closed position.

Figure 2 is an end elevation corresponding to Figure 1.

Figure 3 is a side elevation, partly in section with the breech in open position.

Figure 4 is a top plan View of the cocking mechanism with the breech ring shown in section.

Figures 5 and 6 are, respectively, side and end elevations, of the cocking lever.

Figure 7 is an enlarged sectional view of portions of the firing and cocking mechanism in the breech block taken on the line 11 of Fig. l. The parts are in cocked position.

Figure 8 is an enlarged sectional plan view of a portion of the breech ring including the cocking pin and a portion of the cocking lever.

Referring to the drawing by characters of reference there is shown a breech ring I, having an opening for a vertically sliding breech block 2, the mechanism for operating the block being omitted. The breech block is formed with a bore 3 which houses a firing mechanism 4 of the type referred to in applicants copending application, Serial No. 274,987. The firing mechanism is provided with a laterally extending lug 5 for engagement with the cocking device which is the subject of this. application. The firing mechanism is further provided with means for engaging a sear I provided to maintain the firing mechanism in cocked position until released by the gunner.

The cooking lever 8 (Figs. 5 and 6) is formed with a cylindrical shaft portion 9 having two arms extending therefrom. The upwardly extending arm I9 is flush on its outer surface with the end of the cylindrical portion 9 and is pro- .Vided on its upper curved end with a laterally extending lug l l for a purpose as will hereinafter appear. Between the cylindrical portion 9 and the downwardly extending arm 12 is a spring engaging web l3. The arm is provided on its lower end with a laterally extending lug M. A portion l5 of the cylindrical portion 9 extends beyond the arm I2 to provide a trunnion for the cocking lever.

Milled cuts are provided in the faces of the breech block for lightness and to accommodate the cocking lever, the slot i6 is milled to such a depth that it intersects the bore 3 in which the firing mechanism is housed and a lateral bore I! is formed in the side of the block to a depth equal to the length of the cylindrical portion 9. Below this lateral bore an opening, roughly the shape of a segment of a cylinder, is milled into the block intersecting the slot l8 and the bore I1 and deep enough to accommodate the downwardly extending arm l2 of the cooking lever. The side face of the block has been milled back as best shown in Figure 3 to provide guiding surfaces and to allow the upwardly extending arm to be rotated about the cylindrical shaft without interfering with the operation of the block. Other cuts have been made to reduce weight as far as practicable without dangerously reducing strength. A hole I8 is bored into the block from the front to accommodate a spring l9 and plunger 20.

The cocking lever may be assembled to the block by inserting the spring and plunger into the bore provided for them and while holding them in retracted position inserting the cocking lever from the side, in which position the lug M will extend into the bore 3 in position to engage with the lug 5 on the firing device as shown in Fig. 7. Upon release the plunger 29 will engage the web l3 and bias the lower end of the cooking lever to forward position. Th cooking lever is retained in the block by engagement with the side wall of the block receiving opening in the breech ring.

The rear face of the breech ring is provided with a bore 2| to accommodate a pin 22 and a retaining screw 23. A cylindrical segment is removed from a portion of the end of the pin leaving a reduced portion 24 of the pin which extends through that portion of the bore intersecting the breech block receiving opening in the breech ring and is provided with a cam surface to engage the lug H on the cooking lever, as shown in Fig. 8. The lower edge of 24 is undercut slightly to provide a cam surface to engage the upper surface of the lug II and urge it for-, ward preventing catching when the block is initially inserted in the breech ring.

The breech block operating mechanism functions in a known manner in that'thebreechblock' is drawn downwards against spring pressure after firing and upon striking limiting stops, not shown, tends to return but is engaged. in a known manner by the extractors, not shown, to prevent, such return 'until released by insertion of a new the forwardly facing shoulder formedby the breech, block receiving opening in the breech ring. Near the completion of the downward travel of the. block the lug H engages the cam end of pin 22 and the firing mechanism 4 is completely cocked; As the block rises to the i point of engagement with the extractors, the lug is disengaged from the pin and the firing mechanism moves forward sufficiently to allow the lug 6 to seat upon the sear 1. The positive shifting of the load from cocking lever to sear reduces the wear upon the cooking lever and the face of the breech block with which it engages and speeds the returning action of the block by reducing drag.

Elements of the firing mechanism which are shown but are not directly concerned with the inventive subject matter of this application include a trigger 25 rotatably mounted: in the breech ring and having attached thereto a tripper 26 which engages a cam 21 on the sear I to move the sear laterally for releasing the firing mechanism. The tripper is provided with a depending arm 28 having. a finger. 29 extending across the front face of. the block. When the block is in closed position, the finger is clear to rotate under the corner of the block but, in any other position of the block the finger is restrained by the front face of the block thus positively preventing movement of the trigger to fire the gun except when the block is fully closed. A spring 30 and plunger 3| are provided to bias the trigger to non-firing position.

It will be noted that should the sear break or fail to properly engage the firing pin the engagement of the lug II with the breech ring will graduallylower the firing pin to rest against the rebounding mechanism preventing protrusion of the firing pin and probable breakage as the block rises to closed position.

1. In a gun having a breech block enclosing a firing mechanism and a breech ring in which said block .is, slidably mounted, a cocking mechanism comprising a lever journaled in the breech block, means: on: said lever engageable with said firing mechanism for cocking thereof, an arm on said lever extending beyond the limits of the breech block engaging the breech ring to swing the lever as: the breechis opened, and camming means in said breech ring engaging the lever to further swing. the lever and'cock the firing mechanism as the breech opening'movement is concluded;

2. In a gun having a breech block enclosing a firing; mechanism and a breech ring in which said block is slidably mounted, a cocking mechanism comprising a lever journaled in the breech ring, an armon the lever having means engageable with the firing mechanismfor cocking thereof, a lever-engaging member mounted in the breech ring, and a second arm on the lever successively engageable with the breech ring and the leverengaging member whereby the lever is operated to cock the firing mechanism as the breech is opened.

3. In a: gun having a breech block enclosing a firing mechanism and a breech ring with an opening. in which said block is slidably mounted, a cocking mechanism comprising a cocking lever journaled in the breech block and having means engageable with the firing mechanism for cocking thereof, cocking lever engaging means in the opening in the breech ring and an army on the cooking lever having an end portion successively engageable with the wall of the opening in the breech ring and with said cocking lever engaging, means as the block is operated to open the breech.

WILLIAM SUMMERBELL. 

